I've been using the world imagery layer in ArcMap for hand-digitizing possible restoration sites. This has generally been adequate except for a few instances in which the imagery is a bit old and significant changes (such as the addition of an irrigation pond) have occured. In general the imagery available from Bing is adequate but I don't have a key to access it. I was thinking about just taking screen shots of the specific sites where I've notices discrepancies and georeferencing- does anyone have experience with this, or can you recommend another source for up-to-date imagery of the US pacific northwest?
I suppose even if there are significant changes, you can still find some common things such as river, or architecture etc which remains over the years so try to add control points. If you find common things you can easily follow: https://mdl.library.utoronto.ca/technology/tutorials/how-georeference-images-arcgis and georeference. Furthermore, also check: https://community.esri.com/thread/31486. The accuracy will depend on you as there is no coordinate.